The invention relates to an arrangement for pneumatic false-twist spinning having at least one air nozzle arranged behind a drafting unit, which at least one air nozzle leads into a space provided with a covering that can be swivelled away and has a yarn outlet opening.
For the reduction of noise, it is known from U.S. Pat. No. 4,586,323 to provide a chamber which is covered by means of a covering following an air nozzle of an arrangement for pneumatic false-twisting spinning. This chamber has a yarn outlet opening from which the yarn emerges during the spinning operation. For a piecing operation, the covering of a servicing apparatus is opened so that a yarn intake pipe can be applied directly to the mouth of the air nozzle.
It is also known from German Patent Document DE-A 36 38 110, corresponding to U.S. Pat. No. 4,819,419, to cover the air nozzle toward the outside and the operating side of the machine with a covering which is constructed as a holding element for at least one air nozzle. In this case, it is also known to connect duct-type guiding elements to the mouth of the air nozzle. In an embodiment (FIG. 9), a bifurcated guiding element is connected to two adjacent air nozzles and the yarn guiding ducts of this guiding element leads the yarns together which leave the two adjacent air nozzles which are aligned in a V-shape with respect to one another.
It is an object of the invention to develop an arrangement of the initially mentioned type in such a manner that an effective noise reduction is obtained without any diminishing of the operability of the machine.
This object is achieved according to the invention in that the space is designed as a groove which, by means of a closed covering, is completed to form a yarn guiding duct which leads from the mouth of the air nozzle to the yarn outlet opening. In this manner, it is possible to cover the outlet area of the air nozzle, that is, the area in which the noise is mainly generated. The air can flow off by way of the yarn guiding duct, in the process exercising a transport effect on the spun yarn which can then be taken over at the yarn outlet opening for example, for a piecing operation--without the requirement of having to move the covering for this purpose. In this case, the yarn guiding duct acts as a calming zone for the air emerging from the air nozzle so that a flowing-away from the yarn outlet opening of the yarn guiding duct is not connected with any significant generating of noise.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.